Terminal device, terminal configuration system, and terminal configuration method

ABSTRACT

[Solution] A communication system comprises a server and a terminal device. The server stores first information in order for the terminal device to communicate, and stores second information in order for the terminal device to connect to a network of the other bases. When the power is turned on in a normal operation, the terminal device connects to the network by using network information in a non-volatile memory unit, obtains the first information from the server, and writes the same in a volatile memory unit. Thus, the terminal device starts operation. When the power is turned on by using a particular operation, the terminal device connects to the network by using the network information in the non-volatile memory unit, obtains network information of the other bases from the server, and stores the same in the non-volatile memory unit. Thus, it is possible to connect to the network of the other bases.

TECHNICAL FIELD

The present invention relates to facilitation of relocation of aterminal device in a communication system using a network such as awireless LAN.

BACKGROUND ART

As illustrated in Non-Patent Literature 1, a wireless LAN transceiversystem which is a voice communication system utilizing the wireless LANhas been put into practice. In this system, a plurality of the terminaldevices and a server are connected via a wireless LAN (local areanetwork), a relaying function of the server enables voice communicationbetween terminal devices. The terminal device has a shape resembling ahandy transceiver and realizes a communication form such as full-duplexcommunication or group communication by making use of characteristics ofthe wireless LAN with an impression from use not different fromconventional wireless communication.

CITATION LIST Non-Patent Literature

-   [Non-Patent Literature 1] “IP ADVANCED RADIO SYSTEM”, Icom    Incorporated, Internet    <https://www.icom.co.jp/products/network/ip_advanced_radio_system/>

SUMMARY OF INVENTION Technical Problem

On the other hand, since the aforementioned voice communication systemis a system utilizing a wireless LAN, configuration corresponding toeach device is needed for enabling connection of each device to thenetwork or communication between each of the devices. In the case ofusing a large number of the terminal devices, configuration is neededfor each terminal device, and a work load is increased. Moreover, if theterminal device is relocated among a plurality of bases (voicecommunication systems) or in the case of the terminal device used by auser relocated among the plurality of bases, for example, since theconfiguration is different depending on the base, the configurationneeds to be changed in accordance with the base every time the terminaldevice is relocated, which is cumbersome.

Thus, the present invention has an object to facilitate relocation ofthe terminal device between the bases in the communication system usingthe network such as a wireless LAN.

Solution to Problem

A terminal device of the present invention comprises a networkcommunication unit for processing communication over a network, acontrol unit having a volatile storage unit and a rewritablenon-volatile storage unit, and an operation unit. The volatile storageunit stores terminal configuration information. The non-volatile storageunit stores network information for connection to the network. Whenpower is turned on by a first procedure of the operation unit, thecontrol unit reads out the network information from the non-volatilestorage unit and connects to the network so as to make an access to aserver on the network, to obtain the terminal configuration information,and to write it in the volatile storage unit. When the power is turnedon by a second procedure of the operation unit, the control unit readsout the network information from the non-volatile storage unit andconnects to the network so as to make an access to the server, to obtainsecond network information for connection to a second network differentfrom the network, and to overwrite and store it in the non-volatilestorage unit.

The present invention is effective when the terminal device is relocatedamong a plurality of voice communication systems as below. The voicecommunication system has:

a first voice communication system having:

-   -   a first relaying server installed on a first network and        relaying voice communication between terminal devices connected        to the first network;    -   a first provisioning server for supplying terminal configuration        information to the terminal device; and    -   a first assignment server for giving identification information        to the terminal device and for providing first server        information for making an access to the first provisioning        server to the terminal device; and

a second voice communication system having:

-   -   a second relaying server installed on a second network and        relaying voice communication between the terminal devices        connected to the second network;    -   a second provisioning server for supplying the terminal        configuration information to the terminal device; and    -   a second assignment server for giving the identification        information to the terminal device and for providing second        server information for making an access to the second        provisioning server to the terminal device. The second network        information for connecting to the second network is stored in        the first assignment server, and with respect to the terminal        device, the second network information is written in the first        network. As a result, when this terminal device is used in the        second voice communication system, rapid connection to the        second network can be made so as to make an access to the second        assignment server.

Advantageous Effect of Invention

According to the present invention, configuration at start of theterminal device is facilitated, and manual configuration at each basewhen the terminal device is relocated among the bases is no longernecessary.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a configuration diagram of a voice communication system whichis an embodiment of the present invention.

FIG. 2 is a block diagram of a terminal device.

FIG. 3A is a diagram illustrating a storage area configured in a storageunit of the terminal device.

FIG. 3B is a diagram illustrating an example of storage contents of anFROM of the terminal device.

FIG. 3C is a diagram illustrating an example of storage contents of anFROM of the terminal device.

FIG. 4 is a block diagram of a server.

FIG. 5 is a diagram illustrating a TRX table configured in an assignmentserver.

FIG. 6 is a diagram illustrating a terminal configuration tableconfigured in a relaying server.

FIG. 7 is a diagram illustrating a terminal registration tableconfigured in the relaying server.

FIG. 8 is a diagram illustrating a group table configured in therelaying server.

FIG. 9 is a diagram illustrating a mixing table configured in therelaying server.

FIG. 10 is a diagram illustrating an example of configuration of a voicepacket.

FIG. 11 is a flowchart illustrating writing processing of TRXinformation to the terminal device.

FIG. 12 is a flowchart illustrating a communication procedure of theterminal device and the assignment server.

FIG. 13 is a flowchart illustrating an operation of the terminal device.

FIG. 14 is a flowchart illustrating an operation of the relaying server.

FIG. 15 is a flowchart illustrating the operation of the relayingserver.

FIG. 16 is the terminal device among a plurality of bases.

FIG. 17 is a flowchart illustrating a communication procedure of theterminal device and the assignment server.

DETAILED DESCRIPTION OF THE EMBODIMENT

A voice communication system of the present invention will be describedby referring to the attached drawings. FIG. 1 is a configuration diagramof the voice communication system which is an embodiment of the presentinvention. In this voice communication system, a plurality of terminaldevices 14 communicate with each other by using a wireless LAN (localarea network) 16 such as Wi-Fi. The terminal device 14 has a shaperesembling a handy transceiver for wireless communication and comprisesa PTT (push-to-talk) switch 220 as illustrated in FIG. 2. The terminaldevice 14 is a wireless network device for transmitting/receiving avoice packet via a wireless access point (AP) 13 in view of a function.A server 11 having a relaying function relays mutual communication via awired network 15 and the wireless LAN 16 of the plurality of terminaldevices 14. It should be noted that, hereinafter, the wired network 15and the wireless LAN 16 are collectively called a network 17.

As the wired network 15, Ethernet (registered trademark) LAN or theInternet can be used. If the Internet is included in the wired network15, safe communication can be conducted by using VPN (virtual privatenetwork). As the wireless LAN 16, communication methods conforming toIEEE802.11 such as Wi-Fi can be applied. The terminal device 14 and awireless access point 13 conduct communication with the communicationmethod of this wireless LAN 16. In FIG. 1, three units of the wirelessaccess points 13 are installed, but the number of the wireless accesspoints 13 in this voice communication system is not limited.

The server 11 and a management device 12 are connected to the wirednetwork 15. The server 11 has an assignment server function in charge ofassignment of TRX numbers, a provisioning server function for enablingoperation by configuring data required for the terminal device 14, and arelaying server function for relaying a voice signal. Hereinafter, forfacilitation of understanding, the assignment server function of theserver 11 shall be referred to as an assignment server 11A, theprovisioning server function to a provisioning server 11B, and therelaying server function to a relaying server 11C. It is needless to saythat one or all of the assignment server 11A, the provisioning server11B, and the relaying server 11C may consist of another piece ofhardware. The assignment server 11A automatically assigns a TRX numberwhich is an identification code of the terminal device 14 in this voicecommunication system to the terminal device 14. The relaying server 11Crelays communication between the terminal devices 14. Details ofprocessing of the server 11 will be described later. The managementdevice 12 consists of a personal computer or the like in which amanagement program is installed. The management device 12 makes anaccess to the server 11 in accordance with an operation by anadministrator and configures a table and the like illustrated in FIGS. 5to 8 in the server 11. Moreover, the management device 12 communicateswith the terminal device 14 via a USB and the like and writesinformation illustrated in FIG. 3A in the terminal device 14.

In this voice communication system, the relaying server 11C receives avoice packet (RTP packet) transmitted without an advance notice from theterminal device 14 and on the basis of communication control informationwritten in this voice packet, delivers a voice signal of this packet tothe terminal device 14 of a communication partner. As a result, despitethe voice communication via the network 17, a communicationestablishment procedure such as the SIP procedure is not necessary. Thatis, in this voice communication system, a user does not have to make acalling operation such as dialing but only needs to turn on the PTTswitch 220 of the terminal device 14 and to talk toward a microphone 240so that this voice signal is transmitted to the terminal device 14 ofthe communication partner. As a result, the user can conduct the voicecommunication over the network with an impression from use similar tothe transceiver of conventional wireless communication.

In this voice communication system, the terminal device 14 is capable ofcommunicating in communication forms of individual communication, groupcommunication, and plenary communication. The individual communicationis a one-to-one communication form conducted by the single terminaldevice 14 (calling terminal device) by calling another single terminaldevice 14. The group communication is a form in which the callingterminal device 14 calls a group, and mutual communication is conductedamong the terminal devices belonging to the group. The plenarycommunication is group communication targeted to all the terminaldevices 14 in which the calling terminal device 14 calls all, and mutualcommunication is conducted among all the terminal devices.

FIG. 2 is a block diagram of the terminal device 14. As described above,the terminal device 14 is a wireless network device fortransmitting/receiving a voice packet via the wireless access point (AP)13 of the wireless LAN in view of a function. The control unit 20consists of a microprocessor and controls the operation of the terminaldevice 14. The control unit 20 has a storage unit 21 in which dataillustrated in FIG. 3A is stored. The storage unit 21 has a RAM 21A anda flash ROM 21B. The RAM 21A is used as a work memory during theoperation. The flash ROM (FROM) 21B is used for storing information suchas TRX information and network information in a non-volatile manner. Tothe control unit 20, an operation unit 22, a display unit 23, an audiocircuit 24, and a wireless LAN communication unit 25 are connected. Theoperation unit 22 includes key switches such as the PTT switch 220 andreceives an operation by the user and inputs its operation signal intothe control unit 20. The display unit 23 includes a liquid crystaldisplay. On the liquid crystal display, a terminal number/group numberof the communication partner selected by the operation by the user andthe terminal number/group number of the communication partner ofincoming communication and the like are displayed.

The audio circuit 24 has the microphone 240 and a speaker 241. Thecontrol unit 20 decodes the received voice packet and inputs it into theaudio circuit 24. The audio circuit converts this decoded audio signalto an analog signal and outputs it from the speaker 241. The audiocircuit 24 also converts the voice signal input from the microphone 240to a digital signal and inputs it into the control unit 20. The controlunit 20 makes this digital audio signal packetize to a voice packet andinputs it to the wireless LAN communication unit 25. The wireless LANcommunication unit 25 has a circuit conducting wireless communication inthe communication methods conforming to IEEE802.11. The wireless LANcommunication unit 25 transmits the packet input from the control unit20 to the wireless access point 13. By means of the aforementionedfunctions, when the user utters voice toward the microphone 240 whilepressing on the PTT switch 220, this voice signal is edited into thevoice packet and transmitted to the relaying server 11C. Moreover, thewireless LAN communication unit 25 inputs the packet received from therelaying server 11C via the wireless access point 13 into the controlunit 20.

The terminal device 14 has a VOX circuit 242 together with the PTTswitch 220. The VOX circuit 242 is a circuit which determines whether atalking voice (voice signal) of the user has been input or not on thebasis of an input level of the microphone 240 and its duration and if itis determined that the talking voice has been input, switches the deviceto the same communication state as the case where the PTT switch 220 isturned on. The terminal device 14 carries out switching betweentransmission on/off by mode configuration on the basis of either one ofor both of turning-on of the PTT switch 220 and the VOX circuit 242.

Although a general wireless communication transceiver is that of asimplex type which cannot receive a wireless signal in a transmissionstate, the terminal device 14 is capable of full-duplex typecommunication which conducts transmission and reception of the voicesignal at the same time. This function is realized by a fact that theterminal device 14 is a network communication terminaltransmitting/receiving a voice packet at a high speed over the network17. However, the terminal device 14 edits and transmits the voice packetonly when a talking voice is input by the function of the PTT switch 220or of the VOX circuit 242 so that a soundless voice packet is notcontinuously transmitted even if the full-duplex communication iscarried out.

The terminal device 14 has a storage area illustrated in FIG. 3A in theRAM 21A and the flash ROM 21B. In the flash ROM 21B, the TRX informationand the network information are stored in a non-volatile manner. The TRXinformation includes a TRX number and the server information. The TRXnumber is the identification code of the terminal device 14 in the voicecommunication system as described above, and numerical values of 1 to100 are used in this embodiment and any one of them is assigned to eachof the terminal devices 14 operated in the voice communication system.The server information is information for accessing the server 11 andincludes an IP address and a password. Moreover, the network informationis information for making an access to the network 17 (wireless LAN 16)and includes SSID and authentication information (WEP and the like).These TRX information and network information have contents asillustrated in FIG. 3B, for example, and when the terminal device 14 ispowered on, it is read out of the flash ROM 21B and written in the RAM21A. Moreover, as illustrated in FIG. 3C, the TRX information may beblank. In this case, when the terminal device 14 is powered on, theterminal device 14 is connected to the network 17 on the basis of thenetwork information and makes an access to the assignment server 11A soas to obtain the TRX number and the server information. That is, if theTRX number is blank (Null) indicating automatic assignment (AUTO), theterminal device 14 automatically obtains the TRX information from theassignment server 11A. The obtained TRX number and server informationare not written in the flash ROM 21B but are written only in the RAM21A. Therefore, this content is cleared when the power is turned off.

As described above, assignment methods of the TRX number include manualassignment in which the TRX number is written in the flash ROM 21Bmanually by the management device 12 as in FIG. 3B and automaticassignment in which nothing is written (Null is written) in the flashROM 21B but the TRX number is assigned to the RAM 21A by the assignmentserver 11A as in FIG. 3C. Moreover, the automatic assignment includesstatic assignment in which the TRX number determined in advance isassigned to each of the terminal devices 14 and dynamic assignment inwhich the TRX number which is free at that time is assigned in order.The static assignment is performed by using a MAC address. The MACaddress of the terminal device 14 is associated with a predetermined TRXnumber and registered in the assignment server 11A, and when theterminal device 14 accesses the assignment server 11A (assignmentrequest), the assignment server 11A assigns the TRX number reserved forthe terminal device 14 by collating the MAC address. In the dynamicassignment, when an assignment request is made, the assignment server11A assigns the TRX number which is free at that time to the terminaldevice 14, but the MAC address of the terminal device 14 assigned in thepast in association with each of the TRX numbers is stored, and theassignment server 11A assigns the same TRX number as that in theprevious time to the terminal device 14 as much as possible.

The terminal device 14 makes an access to the provisioning server 11B byusing the TRX information written in the RAM 21A. The provisioningserver 11B carries out provisioning to the terminal device 14 when it isaccessed by the terminal device 14. The provisioning is processing oftransmitting terminal configuration information including the terminalnumber and an update program to the terminal device 14. As a result, theterminal device 14 is set up to an operable state. The terminal device14 makes an access to the relaying server 11C with a given terminalnumber and requests registration. The relaying server 11C registers thisterminal device 14 and enables relaying of this voice signal. Theregistration of the terminal device 14 is made by setting an active flagcorresponding to this terminal number in a terminal registration table(see FIG. 7). The terminal number is used as a calling code for callingthe terminal device 14. The terminal configuration information includesthe terminal number of this terminal device 14, a telephone directorylisting the terminal numbers of the other terminal devices 14 and groupnumbers of communication groups. A value of the terminal number isarbitrary as long as it consists of four or less alphanumeric charactersand unique to each of the terminal devices 14. At appropriate timingafter that, the terminal device 14 requests update of the registrationfrom the relaying server 11C. The appropriate timing after that meansevery certain time, timing when the wireless access point 13 inconnection is switched and the like.

When the terminal device 14 transmits a voice signal to the relayingserver 11C, the terminal device 14 creates a voice packet in which itsown terminal number and a terminal number (or a group number) of thecommunication partner are added to the voice signal and transmits it.Configuration of the voice packet will be described later.

FIG. 4 is a block diagram of the server 11. The server 11 has a controlunit 30, a storage unit 31, and a network communication unit 32. Thestorage unit 31 consists of a hard disk, a RAM: and the like, forexample. The network communication unit 32 controls communication withthe wired network 15. In the storage unit 31 of the server 11, varioustables illustrated in FIGS. 5 to 9 are configured. The control unit 30of the server 11 assigns a free TRX number to the terminal device 14which transmitted an assignment request, carries out provisioning to theterminal device 14 and also carries out mixing and transfer of the voicesignal transmitted from the terminal device 14.

FIG. 5 is a diagram illustrating a TRX table configured in the storageunit 31 of the assignment server 11A. The TRX table is a table forautomatically assigning the TRX information including the TRX number tothe terminal device 14 to which the TRX number has not been manuallyassigned. In the TRX table, TRX numbers which can be assigned to theterminal devices 14 are stored. In association with each of the TRXnumbers, storage areas are provided for the server information, networkinformation, assignment target information, assigned flags, and MACaddresses. The assignment target information is information indicatingthat the TRX number is reserved in advance for the specific terminaldevice 14 (static assignment), that it has not been reserved (dynamicassignment) or it is a dummy TRX number for transmission of the networkinformation. The static assignment is an assignment form in which theTRX number has been reserved in advance for the specific terminal device14 and the TRX number is fixedly assigned to the terminal device 14. Thedynamic assignment is an assignment form in which an assignmentdestination of the TRX number has not been fixed, and a free TRX numberis assigned in order to the terminal device 14 which made an assignmentrequest. The dummy TRX number is associated with the network informationof other bases, and the network information of the base of a relocationdestination is provided to the terminal device 14 by using this TRXnumber as will be described later (see FIGS. 16 and 17). The serverinformation is information such as an IP address or a password foraccessing the server 11 (provisioning server 11B). The networkinformation is information such as BSSID or a password for making anaccess to the network 17 (wireless LAN 16). In items of the serverinformation of the TRX numbers for the dynamic assignment and for thestatic assignment, the information of the server 11 of this voicecommunication system is stored. Moreover, in the items of the networkinformation of the dummy TRX numbers, information for connecting to thenetworks of the other bases (other voice communication systems) isstored. In the items of the network information of the TRX numbers forthe dynamic assignment and for the static assignment, there is no needto write the network information, but the network information of its ownbase (this voice communication system) may be written. Moreover, in theitems of the server information of the dummy TRX numbers, the serverinformation of the other bases corresponding to the network informationdoes not have to be written since an access is made again to theassignment sever 11A at the base of the relocation designation, but theserver information of the other bases or the server information of itsown base may be written.

The assigned flag is a flag indicating that the TRX number has beenassigned to the terminal device 14 at present and is set by theassignment server 11A when the TRX number is assigned to the terminaldevice 14. In the item of the MAC address, the MAC address of (thewireless LAN communication unit 25 of) the reserved terminal device 14is written in the case of the statically assigned TRX number. In thecase of the dynamically assigned TRX number, the MAC address of theterminal device 14 to which the TRX number is assigned is stored in theitem of the MAC address. Once the TRX number is assigned, and when anassignment request is made again from the terminal device 14 which isinactivated after that, the same TRX number is assigned as much aspossible by searching the table with that MAC address. It should benoted that the dummy TRX number is not included in writing targets ofassigned flags and MAC addresses. When all the TRX numbers have beenassigned to the terminal devices 14 (at least once) and there is no moreblank TRX number, if a new assignment request is made, the oldest itemamong those not active at present is reset and assigned to the terminaldevice 14 for which the request was made this time. It should be notedthat, if the terminal device 14 to which the TRX number wasautomatically assigned is made inactive, that fact is notified to theassignment server 11A from the relaying server 11C. Moreover, if timeduring which the terminal device 14 is inactive continues forpredetermined time or more, the assignment server 11A may determine thata lease period to the terminal device 14 has been finished and reset theassigned flag of the TRX number which has been assigned to the terminaldevice 14.

FIG. 6 is a diagram illustrating a terminal configuration tableconfigured in the storage unit 31 of the provisioning server 11B. Theterminal configuration table is used during provisioning to the terminaldevice 14. In the terminal configuration table, the terminal number(calling code) configured to the terminal device 14 of the TRX numberand configuration data for each TRX number are stored. The configurationdata includes update data (firmware) of the program, a telephonedirectory recording the terminal numbers of other communicable terminaldevices 14, groups to which it belongs and the like. Moreover, a flagindicating that the terminal device 14 with that number has beenconfigured in correspondence with each of the TRX numbers is stored. TheTRX numbers are for 100 units numbered from 1 to 100, and in thisconfiguration, 1 to 30 are used for TRX numbers for manual assignment.Moreover, 31 to 100 are used for TRX numbers for automatic assignment.In the TRX table in FIG. 5, the TRX numbers for automatic assignment areregistered. It should be noted that the TRX numbers with 91 to 100 arenumbers for dummy assignment as illustrated in FIG. 5.

FIG. 7 is a diagram illustrating the terminal registration tableprovided in the storage unit 31 of the relaying server 11C. The terminalregistration table is a table for the relaying server 11C to manage theterminal device 14. Each of the terminal devices 14 is identified by theterminal number which is the calling number uniquely assigned to each.In the terminal registration table, the TRX number, an active flag, anIP address, and an identification code (IP address) of the wirelessaccess point 13 in connection of the terminal device 14 are stored foreach of the terminal numbers. The active flag is a flag indicating thatthe terminal device 14 has accessed the relaying server 11C andcompleted registration and is communicable. It should be noted that, inthe server 11, the terminal configuration table for provisioning (FIG.6) and the terminal registration table for registration (FIG. 7) may becombined into one table. It should be noted that, a part of or the wholeof the TRX information and the terminal configuration informationcorresponds to the first information of the present invention.

The provisioning server 11B executes processing of provisioning to theterminal device 14 when a provisioning request is received from theterminal device 14. When provisioning is completed, the terminal device14 makes an access to the relaying server 11C and requests registration.The relaying server 11C writes the IP address in the terminalregistration table and sets the active flag, and registers that it is ina communicable state. Moreover, the relaying server 11C communicateswith the terminal device 14 at appropriate timing after that and updatesthe registration of the terminal device 14. The appropriate timing afterthat means every certain time, timing when the wireless access point 13in connection is switched and the like.

The relaying server 11C further comprises a group table and a mixingtable in order to control communication between the terminal devices 14(transfer of a voice signal). FIG. 8 is a diagram illustrating the grouptable. The group table is a table for the relaying server 11C to managethe group. Each of the groups is identified by an ID (group number)uniquely assigned to each. In the group table, the group number and theterminal number of the terminal devices 14 (belonging terminal devices)belonging to the group are stored for each group.

FIG. 9 is a diagram illustrating the mixing table (session table). Themixing table is a table for the relaying server 11C to manage acommunication session. The communication session is a communicationstate among a plurality of the terminal devices 14 using the relayingserver 11C as a relaying device. The mixing table has a plurality ofrows, and information for one communication session is stored in eachrow. The relaying server 11C determines from which of the communicationsessions the voice signal comes by referring to the mixing table when itreceives the voice signal (voice packet) from the terminal device 14.

When the relaying server 11C receives a calling voice packet which is afirst voice packet from the terminal device 14, the communicationsession based on this voice packet is registered in the mixing table.

In the mixing table, items for a session number, a calling terminalnumber, a participating terminal number, and remaining retention time(T1) are provided for each communication session. The session number isa number for identifying this communication session. The callingterminal number is a terminal number of the terminal device 14 (callingterminal device) which transmitted the first voice packet (calling voicepacket) of this communication session. As the session number, acommunication partner identification number written in the calling voicepacket is used. The communication session for which the terminal numberis registered as the session number (“19”, for example) is thecommunication session of the individual communication. The individualcommunication is one-to-one communication between the individualterminal devices 14. The communication session for which the groupnumber is registered as the session number (“0012”, for example) is thecommunication session of the group communication. The groupcommunication is communication in which a plurality of the terminaldevices 14 (three or more in general) mutually exchange voice signals.

The participating terminal number is a list of the terminal numbers ofthe terminal devices 14 participating in this communication session.When a voice packet is transmitted from one of the terminal devices 14whose terminal number is registered in the participating terminalnumber, the control unit 30 transfers this voice packet to anotherterminal device 14 whose terminal number is registered in theparticipating terminal number and realizes mutual communication betweenthe participating terminal devices.

In the case of the group communication session, the participatingterminal numbers are the terminal number of the calling terminal deviceand the terminal number of the terminal device 14 belonging to the groupspecified by the communication partner.

The retention time is time held without canceling this communicationsession in a state where the voice packet is not transmitted from theparticipating terminal device. The retention time of each communicationsession in the relaying server 11C is set to 30 seconds, for example. Aretention time timer (TS) of the mixing table is a timer for countingelapse of the retention time if a voice packet is not transmitted. Theretention time timer TS is counted down if the voice packet is nottransmitted and is reset to 30 seconds if the voice packet istransmitted in processing by the control unit 30 (see FIG. 15). When thevoice packet is not sent for 30 seconds from the participating terminaldevice and the timer TS's time is up, this communication session iscancelled, and the information of this communication session is erasedfrom the mixing table.

Moreover, in order for the communication session to be continued, theretention time needs to be counted also in each of the terminal devices14. The retention time (T1) of the terminal device 14 is shorter thanthe retention time (TS=30 seconds) of the relaying server 11C and is setto 5 seconds, for example, in a timer T1. When 5 seconds have elapsedsince the PTT switch 220 was turned off, even if the communicationsession is maintained in the relaying server 11C, the user can startanother communication session by a predetermined operation.

The voice packet has configuration as illustrated in FIG. 10. The voicepacket is made of a header and a data body (payload). The headerincludes a destination IP address (destination address) and atransmission source address (sender address). In the case of the voicepacket transmitted from the terminal device 14 to the relaying server11C, the destination IP address is an IP address of the relaying server11C, and the transmission source address is an IP address of theterminal device 14. In the case of the voice packet transmitted from therelaying server 11C to the terminal device 14, the destination IPaddress is the IP address of the terminal device 14, and thetransmission source address is the IP address of the relaying server11C. The data body contains communication control information togetherwith digitized voice signals. The communication control informationincludes a calling type, a calling ID and a source ID. The calling typeis information for identifying a communication type (individualcommunication, group communication, plenary communication) of this voicepacket. The calling ID is information for identifying the communicationpartner (target device), and in the case of the individualcommunication, the terminal number of the terminal device 14 is used,while in the case of the group communication, the group number of thegroup is used.

The source ID is information indicating a source of the voice signal. Inthe case of the voice packet transmitted from the terminal device 14 tothe relaying server 11C, the terminal number of the terminal device 14is written in the source ID. The voice signal made into a voice packetand transmitted from the terminal device 14 is transferred onto anothervoice packet in the relaying server 11C and is transferred to theterminal device 14 of the communication partner. In the terminal device14 of the communication partner, too, the terminal ID of the terminaldevice 14 which transmitted the voice signal is written in the source IDof the voice packet transferred from the relaying server 11C to theterminal device 14 so that the source of the received voice signal isknown. In the case of the group communication, a signal in which thevoice signals received from the plurality of terminal devices 14 aremixed is packetized and transferred to the terminal device 14 in somecases, but the source ID of this voice packet may be cleared, or thegroup number may be written therein.

In the case of the group communication, the voice signals received fromthe plurality of terminal devices 14 participating in the groupcommunication are mixed and transferred to each of the terminal devices14 participating in the group communication. In this case, the mixing iscarried out separately for each of the terminal devices 14 so that thevoice signal transmitted by each terminal device 14 is not returned toitself. That is, to the terminal device 14 which has not transmitted avoice signal, the signal in which all the received voice signals aremixed is transferred, while to the terminal device 14 which transmittedthe voice signal, the voice signal transmitted by the terminal device 14is removed and the voice signal in which the other voice signals aremixed is transferred. As a result, an echo of the voice signaltransmitted by the terminal device 14 is not generated therein.

FIG. 11 is a flowchart illustrating processing of TRX informationwriting carried out to the terminal device 14. The terminal device 14 isconnected to a computer such as the management device 12, and thiswriting is carried out. First, the terminal device 14 (control unit 20)determines whether an input of the assignment mode of the administratoris automatic assignment or not (S101). If it is the automatic assignment(YES at S101), the terminal device 14 clears the item of the TRX numberin the flash ROM 21B or writes the information (Null or the like)indicating the automatic assignment (S102) and finishes the processing.If it is not the automatic assignment (NO at S101), the terminal device14 receives inputs of the TRX number and the server information (IPaddress, password and the like) by the administrator (S103), writes theinput TRX number and server information in the flash ROM 21B (S104) andfinishes the processing.

FIG. 12 is a diagram illustrating a communication procedure with theserver 11 from when the terminal device 14 is powered on until thecommunication is enabled. When the terminal device 14 is powered on(S110), the terminal device 14 reads out the network information storedin the flash ROM 21B into the RAM 21A and connects to the network 17(S111). Subsequently, the terminal device 14 refers to the TRX number inthe flash ROM 21B and determines whether it has content (Null)indicating the automatic assignment or not (S112). If it is not thecontent indicating the automatic assignment (NO at S112), the processproceeds to S113.

If the TRX number in the flash ROM 21B has the content indicating theautomatic assignment at S112 (YES at S112), the terminal device 14transmits a message, that the assignment server 11A is searched, to thenetwork 17 by broadcast (S114). The assignment server 11A receives itand replies to the terminal device 14 (S121). The terminal device 14transmits an assignment request of the TRX number in response to thisreply and transmits required information such as the MAC address (S115).The assignment server 11A having received this information selects andassigns a predetermined TRX number to this terminal device 14 (S122) andtransmits the TRX information including the assigned TRX number and theserver information to the terminal device 14 (S123). The assignmentserver 11A sets an assigned flag corresponding to the assigned TRXnumber in the TRX table (S124).

At S122, in the case of the static assignment, the assignment server 11Aselects the TRX number reserved in advance. In the case of the dynamicassignment, it selects one from unused TRX numbers. At this time, if theMAC address of the terminal device 14 is stored in association with anyone of the TRX numbers, the number is selected. In the item of the MACaddress of the selected TRX number, the MAC address of the assignedterminal device 14 is written.

The terminal device 14 receives the TRX information from the assignmentserver 11A at S116. The terminal device 14 makes an access to theprovisioning server 11B by using this information and requestsconfiguration (provisioning) (S117). Moreover, if the TRX number writtenin the flash ROM 21B is not the content indicating the automaticassignment but an actual TRX number at S112, the terminal device 14reads out the TRX number in the flash ROM 21B and the server informationinto the RAM 21A (S113) and makes an access to the provisioning server11B by using this information and requests the configuration(provisioning) (S117).

In response to this, the provisioning server 11B having received theterminal configuration request transmits the terminal configurationinformation including the terminal number (S131) and sets a configuredflag of the terminal configuration table (S132). The terminal device 14receives this terminal configuration information and writes it in theRAM 21A (S118). The terminal device 14 transmits a registration requestto the relaying server 11C (S119). At this time, the terminal device 14transmits information such as the IP addresses of itself and thewireless access point 13 in connection to the relaying server 11C. Therelaying server 11C receives these pieces of information and registersthem in the terminal registration table (S133) and sets an active flagin the terminal registration table (S134). As a result, theconfiguration is completed, and the terminal device 14 can now conductvoice communication with this voice communication system.

FIG. 13 is a flowchart illustrating communication control processingexecuted by the control unit 20 of the terminal device 14. Thisprocessing is repeatedly executed every 20 milliseconds. In thisprocessing, a current communication status (status) is determined inaccordance with ON/OFF of the PTT switch 220 or reception of a voicepacket (RTP packet). Here, flags and timers used in this flowchart areas follows.

PTT: Abbreviation of the push-to-talk switch (PTT switch) 220, but it isnot limited to ON/OFF of the PTT switch 220 but also includes ON/OFF ofa transmission signal by the VOX circuit.

NC0: An identification number (terminal number/group number) of thecommunication partner selected by the operation of the user, which iswritten in the first voice packet (calling voice packet) with which thecommunication session is established and becomes a session number (NC1).

NC1: A session number (calling ID) and a number identifying thecommunication session being carried out.

FC: A communication session flag (flag indicating that this terminaldevice 14 is participating in the communication session).

FT: A during-communication flag (flag indicating that a voice packet isbeing transmitted or received)

T1: A retention time timer (timer for counting retention time (5seconds) of a communication session)

S10 to S20 are transmission management processing of a voice packet. Thecontrol unit 20 determines a state of the PTT switch 220 (S10). If thePTT switch 220 is ON, the control unit 20 proceeds the processing toS11. If the PTT switch 220 is not ON, it proceeds the processing to S20.

At S11, the control unit 20 determines whether the communication sessionflag FC has been set or not. If the communication session flag FC hasnot been set (NO at S11), the voice packet generated by turning-on ofthe PTT switch 220 this time is a calling voice packet. The control unit20 sets the communication flag FC and the during-communication flag FTindicating that the voice packet is being transmitted/received (S12).The control unit 20 transcribes the communication partner number NC0selected by the user to the communication session number NC1 (S13),creates a voice packet in which this communication session number NC1and a user group number stored in an area 213 are written (S14), andtransmits this voice packet to the relaying server 11C (S15). By meansof transmission of this calling voice packet, the communication sessionis started by the relaying server 11C. The control unit 20 resets theretention time timer T1 to 5 seconds (S16) and then, proceeds theprocessing to reception management processing of the voice packet at S30and after.

If the communication session flag FC has been already set at S11 (YES atS11), the control unit 20 determines whether the during-communicationflag FT has been set or not, that is, whether the voice packet is beingtransmitted or received at present (S17). If the during-communicationflag FT has not been set (NO at S17), the control unit 20 sets theduring-communication flag FT (S18). The processing proceeds in the orderof S11→S17→S18 when transmission of a new voice packet (talking voice ofthe user) is started in a state where the communication session whichhas been already started is maintained. After that, the control unit 20proceeds the processing to S14.

At S10, if the PTT switch 220 has not been turned on (NO at S10), thecontrol unit 20 resets the during-communication flag FT (S20). It shouldbe noted that, if the during-communication flag FT has been alreadyreset, it may remain as it is. After that, the control unit 20 proceedsthe processing to the reception management processing of the voicepacket at S30 and after.

The control unit 20 determines whether the voice packet has beenreceived or not over the network 17 at S30. If the voice packet has beenreceived, the control unit 20 proceeds the processing to S31. If thevoice packet has not been received, it proceeds the processing to S40.

At S31, the control unit 20 determines whether the communication sessionflag FC has been set or not. If the communication session flag FC hasnot been set (NO at S31), it determines that a new communication sessionhas been established this time and its first voice packet has beentransmitted and sets the communication session flag FC and theduring-communication flag FT (S33). The FT flag is a flag indicatingthat the voice packet is being transmitted/received at present. Thecontrol unit 20 transcribes the communication partner number included inthe voice packet to the communication session number NC1 (S34). Thecontrol unit 20 outputs the voice packet to the audio circuit 24 (S35)and resets the retention time timer T1 to 5 seconds (S36).

If the communication session flag FC has been already set at S31 (YES atS31), the control unit 20 sets the during-communication flag FT inresponse to reception of the present voice packet (S32). It should benoted that, if the during-communication flag FT has been already set, itmay remain as it is. After that, the control unit 20 proceeds theprocessing to S35.

If the voice packet has not been received at S30 (NO at S30), thecontrol unit 20 determines whether the communication session flag FC hasbeen set or not (S40). If the communication session flag FC has been set(YES at S40), the control unit 20 executes the processing at S41 andafter. If the communication session flag FC has not been set (NO atS40), the control unit 20 finishes the processing as it is.

At S41, the communication unit 20 determines whether theduring-communication flag FT has been set or not. If theduring-communication flag FT has been set (YES at S41), the control unit20 finishes the processing as it is. If the during-communication flag FThas not been set (NO at S41), that is, the during-communication flag FThas been reset but the communication flag FC has been set, the controlunit 20 subtracts 1 count (for 20 milliseconds) from the retention timetimer T1 (S42). Then, it is determined whether the retention time timerT1 has become 0 by this subtraction or not (S43). If the retention timetimer T1 has become 0 (YES at S43), the control unit 20 resets thecommunication session flag FC in order to cancel the communicationsession (S44). If the retention time timer T1 is still larger than 0 atS43 (NO at S43), the control unit 20 finishes the processing as it is.

FIGS. 14 and 15 are flowcharts illustrating an operation of the relayingserver 11C. FIG. 14 illustrates processing at reception of the voicepacket. FIG. 15 illustrates mixing table management processing.

In FIG. 14, when the control unit 30 of the relaying server 11C receivesa voice packet from the terminal device 14 (S50), it determines whetherthe communication session identified by the source terminal number ofthe voice packet and the communication partner number has been alreadyregistered in the mixing table or not (S51). If the communicationsession has been already registered in the mixing table (YES at S51),the control unit 30 transfers the voice signal included in the receivedvoice packet to the terminal device 14 participating in thecommunication session based on the participating terminal number of themixing table (S56). Then, the retention time timer TS of thecommunication session in the mixing table is reset to 30 seconds (S57).

If the communication session of the received voice packet is notregistered in the mixing table (NO at S51), that is, if this voicepacket is a calling voice packet, the control unit 30 registers a newcommunication session based on this calling voice packet in the mixingtable (S52). At this time, the communication partner number isregistered as a session number, and the terminal number of the terminaldevice 14 of the sender of this voice packet is registered as thecalling terminal number. As the participating terminal number, thecommunication partner number and the calling terminal number areregistered in the case of the individual communication session, and thecalling terminal number and the terminal number of the terminal device14 belonging to the group of the communication partner number areregistered in the case of the group communication session.

The control unit 30 transfers the voice signal of the received voicepacket to the terminal device 14 participating in the communicationsession (S53). The terminal device 14 participating in the communicationsession is determined from the participating terminal number of thecommunication session registered in the mixing table.

The mixing table management processing in FIG. 15 is repeatedly executedregularly (every 20 milliseconds, for example). The control unit 30first specifies the communication session on the first row of the mixingtable (S70). The control unit 30 subtracts 1 count (20 milliseconds)from the retention time timer TS of the specified communication session(S71) and determines whether the retention time timer TS has become 0 bythis subtraction or not (S72). If the retention time timer TS has become0 (YES at S62), the control unit 30 determines that this communicationhas been finished and deletes the communication session on this row(S73). The control unit 30 manages the mixing table by sequentiallyexecuting the aforementioned processing until the last row of the mixingtable (S74, S75).

As illustrated in FIG. 16, a plurality of the aforementioned voicecommunication systems are constructed in some cases. That is, a firstvoice communication system is configured at a base 1 and a second voicecommunication system at a base 2. Then, some of the terminal devices 14move back and forth between these bases (base 1, base 2). In the case ofsuch terminal devices 14, by setting the TRX information to theautomatic assignment, that is, by making the TRX number blank, the TRXinformation according to the respective bases (voice communicationsystem) can be received from the assignment servers 11A of the bothbases, and it is no longer necessary to manually configure the TRXinformation at each relocation to another base. However, the networkinformation for connection to the network 17 at each base is preferablyconfigured when it is connected to the network 17 of the previous basebefore relocated to the base. Each of the bases may be spatially awayfrom each other, or the network 17 may be separated as they aredifferent sections at neighboring locations. The number of bases is notlimited to 2.

FIG. 17 is a diagram illustrating a procedure of processing of theterminal device 14 for obtaining the network information from theassignment server 11A. This processing is processing executed whilepower is on for a short time in order to obtain the network informationof the next base. This processing is processing executed by the terminaldevice 14 which has finished operation at one base and is to berelocated to the next base. This is a diagram illustrating theprocessing that, after the operation is finished, power is turned offonce and then, in order to obtain the network information of the nextbase, power is turned on again while a control button is pressed (secondprocedure of the present invention), and an access is made to theassignment server 11A. It should be noted that, a normal operation ofpowering-on without operating other buttons (at least the controlbutton) corresponds to the first procedure of the present invention.

In FIG. 17, when the terminal device 14 is powered on in a state wherethe control button is pressed (S140), the terminal device 14 reads outthe network information stored in the flash ROM 21B (of this base) intothe RAM 21A and connects to the network 17 (S141). Subsequently, itrefers to the TRX number in the flash ROM 21B and determines whether thenumber has the content (Null) indicating the automatic assignment or not(S142). If the TRX number in the flash ROM 21B has the contentsindicating the automatic assignment (YES at S142), the terminal device14 transmits a message, that the assignment server 11A is searched bybroadcast, to the network 17 (S143). The assignment server 11A receivesthis and replies to the terminal device 14 (S150). The terminal device14 transmits a message to request a list of the network information inresponse to this reply (S144). The assignment server 11A transmits listsof the dummy TRX numbers (091 to 100 in FIG. 5) and base names (branchnames) associated with them in response to that (S151). The terminaldevice 14 displays the base names (or the TRX numbers and the basenames) listed in this list to the display unit 23 (S145), and any one ofthe bases is selected by the user who saw this display (S146). Theterminal device 14 returns the TRX number corresponding to this selectedbase to the assignment server 11A and requests the terminalconfiguration (provisioning) (S147). The assignment server 11A carriesout provisioning in response to this configuration request (S152). Theprovisioning is carried out by transmitting the dummy configurationinformation corresponding to the selected TRX number to the terminaldevice 14. This dummy configuration information includes the networkinformation of the selected base. The terminal device 14 having receivedthis configuration information writes the received network informationin the flash ROM 21B (S148). After the aforementioned processing isfinished, the power is turned off by the user (S149), and the processingis finished. The provisioning based on the dummy data is carried out atS152, but it has no problem because, when the power is turned on at thebase of the relocation destination, the operation in FIG. 12 isexecuted, and new configuration information excluding the networkinformation is downloaded. Moreover, if the power is turned on in thestate where the control button is being pressed at S140, it may be soconfigured that the power is automatically turned off at S149. It shouldbe noted that, by displaying the base name on the display unit 23 atS145, selection of the network information (base) is facilitated.

When the power is turned on next time by the aforementioned processing,the terminal device 14 searches the network 17 on the basis of the newnetwork information written in this flash ROM 21B and makes connection.

It should be noted that, if the TRX number is not the content (Null)indicating the automatic assignment at S112 (NO at S112), since theactual TRX information has been written by a manual operation, theprocessing is finished without executing the processing at S114 to S142.It should be noted that, even in this case (in the case of manualconfiguration), it may be so configured that the network information canbe selected by proceeding to S143. If the actual TRX information hasbeen written, even if the power has been turned on while the controlbutton is pressed, normal start may be made by jumping from S142 to S113in FIG. 12.

Moreover, it may also be so configured that normal start is made even ifthe power is turned on in the state where the control button is beingpressed. In this case, at S123 in FIG. 12, the assignment server 10Aonly needs to transmit the TRX number (dynamic assignment/staticassignment) selected for this terminal device 14 and the dummy TRXnumber list together to the terminal device 14. In the TRX number list,the substantial TRX number selected for the terminal device 14 is set asdefault (head of the list). It may be so configured that, if theterminal device 14 proceeds to the subsequent processing while thepredetermined selection operation (the predetermined operation of thepresent invention) is not performed, this substantial TRX number isautomatically selected, and when the dummy TRX number is selected whilethe list is displayed, the processing at S145 to S149 in FIG. 17 isexecuted.

REFERENCE NUMERALS

-   11 server-   11A assignment server-   11B provisioning server-   11C relaying server-   12 management device-   13 wireless access point-   14 terminal device-   16 wireless LAN-   17 network

What is claimed is:
 1. A terminal device comprising: a networkcommunication unit for processing communication over a first network anda second network; a control unit having a volatile storage unit and arewritable non-volatile storage unit; and an operation unit, wherein thevolatile storage unit stores terminal configuration information, thenon-volatile storage unit stores single network information forconnection to the first network or the second network, when power isturned on by a user input to perform a first procedure of the operationunit for allowing the terminal device to connect to the first network,the control unit reads out first network information from thenon-volatile storage unit and connects to the first network so as tomake an access to a server on the first network, to obtain the terminalconfiguration information, and to write the terminal configurationinformation in the volatile storage unit, when the power is turned on bythe user input to perform a second procedure of the operation unit forconfiguring the terminal device, the control unit reads out the firstnetwork information from the non-volatile storage unit and connects tothe first network so as to make an access to the server on the firstnetwork, to obtain one second network information selected from aplurality of second network information stored in the server on thefirst network by an operation of the operation unit for connection to asecond network, and to overwrite and store the one second networkinformation in the non-volatile storage unit as the network information,the second network is different from the first network, andcommunication under the second network is independent from communicationunder the first network, and in the second procedure of the operationunit, the one second network information is obtained and stored in thenon-volatile storage unit before the terminal device enters in thesecond network.
 2. The terminal device according to claim 1, wherein theserver includes an assignment server and a provisioning server, whenpower is turned on by the first procedure, the control unit makes atfirst an access to the assignment server so as to obtain anidentification code of the terminal device, and then makes an access tothe provisioning server so as to obtain the terminal configurationinformation corresponding to the identification code, and when the poweris turned on by the second procedure, the control unit makes an accessto the assignment server so as to obtain the one second networkinformation.
 3. A terminal configuration system comprising: a firstserver installed on a first network; a second server installed on asecond network; and a terminal device connectable to the first andsecond networks, wherein the first server stores terminal configurationinformation for the first network information and a plurality of secondnetwork information for connection to the second network, the terminaldevice comprises: a volatile storage unit in which the terminalconfiguration information is written; a rewritable non-volatile storageunit in which single first network information for connection to thefirst network is stored as the network information; and an operationunit, when power is turned on by a user input to perform a firstprocedure of the operation unit for allowing the terminal device toconnect to the first network, the terminal device reads out the firstnetwork information from the non-volatile storage unit and connects tothe first network so as to obtain the first terminal configurationinformation from the first server and to write the first terminalconfiguration information in the volatile storage unit, when the poweris turned on by the user input to perform a second procedure of theoperation unit for configuring the terminal device, the terminal devicereads out the single first network information from the non-volatilestorage unit and connects to the first network so as to obtain onesecond network information selected from the plurality of second networkinformation by an operation of the operation unit for connection fromthe first server and to overwrite and store the one second networkinformation in the non-volatile storage unit as the network information,the second network is different from the first network, andcommunication under the second network is independent from communicationunder the first network, and in the second procedure of the operationunit, the one second network information is obtained and stored in thenon-volatile storage unit before the terminal device enters in thesecond network.
 4. The terminal configuration system according to claim3, wherein the first server includes: an assignment server for giving anidentification code to the terminal device; and a provisioning serverfor supplying the terminal configuration information to the terminaldevice, when power is turned on by the first procedure, the terminaldevice makes at first an access to the assignment server so as to obtainan identification code of the terminal device, and then makes an accessto the provisioning server so as to obtain the first terminalconfiguration information corresponding to the identification code, andwhen the power is turned on by the second procedure, the terminal devicemakes an access to the assignment server and obtains the one secondnetwork information.
 5. A terminal configuration method, wherein in avoice communication system having: a first relaying server installed ona first network and relaying voice communication between terminaldevices connected to the first network, a first provisioning server forsupplying the terminal device with terminal configuration informationfor allowing the voice communication by accessing the first replayserver through the first network, a first assignment server for givingidentification information to the terminal device and for providingfirst server information for making an access to the first provisioningserver to the terminal device; a second relaying server installed on asecond network and relaying voice communication between the terminaldevices connected to the second network, a second provisioning serverfor supplying the terminal device with the terminal configurationinformation for allowing the voice communication by accessing the secondrelay server through the second network, a second assignment server forgiving the identification information to the terminal device and forproviding second server information for making an access to the secondprovisioning server to the terminal device, the second network beingdifferent from the first network, communication under the second networkbeing independent from communication under the first network, the secondprovisioning server being different from the first provisioning server,the second assignment server being different from the first assignmentserver; and the terminal device comprising a rewritable non-volatilestorage unit for storing network information for connection to the firstnetwork or the second network and a volatile storage unit in which theterminal configuration information is written, the method including:allowing the first assignment server further to store second networkinformation for connection to the second network; allowing the secondassignment server further to store first network information forconnection to the first network; in a cover area of the first network,based on a user input from the terminal device, performing a procedurefor connecting the terminal device, in which the first networkinformation is stored in the non-volatile storage unit as networkinformation, to the first network on the basis of the first networkinformation stored in the non-volatile storage unit so as to obtain thesecond network information from the first assignment server and tooverwrite and store in advance the second network information in thenon-volatile storage unit before the terminal device enters in thesecond network; after moving from the cover area of the first networkinto a cover area of the second network, connecting the terminal deviceto the second network on the basis of the second network informationstored in the non-volatile storage unit obtained before entering to thecover area of the second network, so as to obtain the second serverinformation from the second assignment server and to make an access tothe second provisioning server; obtaining the terminal configurationinformation from the second provisioning server; and making an access tothe second relaying server by using the terminal configurationinformation.